<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>乘法表</title>
  <style>
    td{
      border: 1px solid black;
      padding:15px;
    }
    table
    {
      border-collapse:collapse;
    }
  </style>
  <script>
    // BOM对象: 警告框,通过浏览器打开一个警告框
    //alert()
    // DOM对象: 向body标签中输出内容
    document.write("<h1 align='center'>九九乘法表</h1>");
    document.write("<table align='center'>")
    for (let i = 1; i < 10; i++) {
      document.write("<tr>")
      for (let j = 1; j <= i; j++) {
            document.write("<td>"+j+" * "+i+" = "+(j*i)+"</td>");
      }
      document.write("</tr>")
    }
    document.write("</table>")
  </script>
</head>
<body>

</body>
</html>